[PATCH net v2] net: renesas: rswitch: fix forwarding offload statemachine

[PATCH net v2] net: renesas: rswitch: fix forwarding offload statemachine

[Michael Dege]

A change of the port state of one port, caused the state of another
port to change. This behvior was unintended.

Signed-off-by: Michael Dege <michael.dege@renesas.com>
---
A change of the port state of one port, caused the state of another
port to change. This behvior was unintended.

Fixes: b7502b1043de86967ff341819d05e09a8dbe8b2b ("net: renesas: rswitch: add offloading for L2 switching")

Changes in v2:
- Implemented suggested improvements to the function.
- Addded missing condition to an if statement.
- introduced bool variable, to reduce the the logic in the if
  statements.
- Link to v1: https://lore.kernel.org/r/20260205-fix-offloading-statemachine-v1-1-640224a531d0@renesas.com
---
To: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
To: Andrew Lunn <andrew+netdev@lunn.ch>
To: David S. Miller <davem@davemloft.net>
To: Eric Dumazet <edumazet@google.com>
To: Jakub Kicinski <kuba@kernel.org>
To: Paolo Abeni <pabeni@redhat.com>
To: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
To: Michael Dege <michael.dege@renesas.com>
Cc: netdev@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/net/ethernet/renesas/rswitch_l2.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/renesas/rswitch_l2.c b/drivers/net/ethernet/renesas/rswitch_l2.c
index 4a69ec77d69c..9433cd8adced 100644
--- a/drivers/net/ethernet/renesas/rswitch_l2.c
+++ b/drivers/net/ethernet/renesas/rswitch_l2.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Renesas Ethernet Switch device driver
  *
- * Copyright (C) 2025 Renesas Electronics Corporation
+ * Copyright (C) 2025 - 2026 Renesas Electronics Corporation
  */
 
 #include <linux/err.h>
@@ -60,6 +60,7 @@ static void rswitch_update_l2_hw_learning(struct rswitch_private *priv)
 static void rswitch_update_l2_hw_forwarding(struct rswitch_private *priv)
 {
 	struct rswitch_device *rdev;
+	bool new_forwarding_offload;
 	unsigned int fwd_mask;
 
 	/* calculate fwd_mask with zeroes in bits corresponding to ports that
@@ -73,8 +74,9 @@ static void rswitch_update_l2_hw_forwarding(struct rswitch_private *priv)
 	}
 
 	rswitch_for_all_ports(priv, rdev) {
-		if ((rdev_for_l2_offload(rdev) && rdev->forwarding_requested) ||
-		    rdev->forwarding_offloaded) {
+		new_forwarding_offload = (rdev_for_l2_offload(rdev) && rdev->forwarding_requested);
+
+		if (new_forwarding_offload || rdev->forwarding_offloaded) {
 			/* Update allowed offload destinations even for ports
 			 * with L2 offload enabled earlier.
 			 *
@@ -84,13 +86,10 @@ static void rswitch_update_l2_hw_forwarding(struct rswitch_private *priv)
 				  priv->addr + FWPC2(rdev->port));
 		}
 
-		if (rdev_for_l2_offload(rdev) &&
-		    rdev->forwarding_requested &&
-		    !rdev->forwarding_offloaded) {
+		if (new_forwarding_offload && !rdev->forwarding_offloaded)
 			rswitch_change_l2_hw_offloading(rdev, true, false);
-		} else if (rdev->forwarding_offloaded) {
+		else if (!new_forwarding_offload && rdev->forwarding_offloaded)
 			rswitch_change_l2_hw_offloading(rdev, false, false);
-		}
 	}
 }
 

---
base-commit: f14faaf3a1fb3b9e4cf2e56269711fb85fba9458
change-id: 20260205-fix-offloading-statemachine-1d301630a08d

Best regards,
-- 
Michael Dege <michael.dege@renesas.com>

Re: [PATCH net v2] net: renesas: rswitch: fix forwarding offload statemachine

[Jakub Kicinski]

On Thu, 05 Feb 2026 14:35:21 +0100 Michael Dege wrote:
> A change of the port state of one port, caused the state of another
> port to change. This behvior was unintended.
> 
> Signed-off-by: Michael Dege <michael.dege@renesas.com>
> ---
> A change of the port state of one port, caused the state of another
> port to change. This behvior was unintended.
> 
> Fixes: b7502b1043de86967ff341819d05e09a8dbe8b2b ("net: renesas: rswitch: add offloading for L2 switching")

Please wait 24h before posting a next version of a patch per:

https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#tl-dr

The Fixes tag is not in the right place here, it should be above your
SoB and the hash is too long (consult the Documentation/ for exact
format)
-- 
pw-bot: cr

RE: [PATCH net v2] net: renesas: rswitch: fix forwarding offload statemachine

[Michael Dege]

Hello Jakub,

Thank you for your comment.

> -----Original Message-----
> From: Jakub Kicinski <kuba@kernel.org>
> Sent: Thursday, February 5, 2026 5:07 PM
> To: Michael Dege <michael.dege@renesas.com>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>; Andrew Lunn <andrew+netdev@lunn.ch>; David
> S. Miller <davem@davemloft.net>; Eric Dumazet <edumazet@google.com>; Paolo Abeni <pabeni@redhat.com>;
> Nikita Yushchenko <nikita.yoush@cogentembedded.com>; netdev@vger.kernel.org; linux-renesas-
> soc@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH net v2] net: renesas: rswitch: fix forwarding offload statemachine
>
> On Thu, 05 Feb 2026 14:35:21 +0100 Michael Dege wrote:
> > A change of the port state of one port, caused the state of another
> > port to change. This behvior was unintended.
> >
> > Signed-off-by: Michael Dege <michael.dege@renesas.com>
> > ---
> > A change of the port state of one port, caused the state of another
> > port to change. This behvior was unintended.
> >
> > Fixes: b7502b1043de86967ff341819d05e09a8dbe8b2b ("net: renesas:
> > rswitch: add offloading for L2 switching")
>
> Please wait 24h before posting a next version of a patch per:
>
> https://www.kernel.org/doc/html/next%252
> Fprocess%2Fmaintainer-netdev.html%23tl-
> dr&data=05%7C02%7Cmichael.dege%40renesas.com%7C22dc6b8fb523473170cc08de64d0a6b3%7C53d82571da1947e49cb4
> 625a166a4a2a%7C0%7C0%7C639059044486368599%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAu
> MDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=WN7Lp3B4q2jOl9REKdbaoVtL1o
> Nr7%2FVME%2BPCJQxoPg4%3D&reserved=0
>
> The Fixes tag is not in the right place here, it should be above your SoB and the hash is too long
> (consult the Documentation/ for exact
> format)
> --
> pw-bot: cr

I will fix the issues.

Best regards,

Michael